If determinism happens to be true, then people just do what the laws of Physics governing the chemical interactions of neurons in their brains make them do. In such a scenario, wouldn't it be unfair to punish people in Hell (or any other form of eternal punishment for that matter)?
If determinism is true, then people have no choice but to do what they are determined to do, including those people who behave immorally. If the goal is to put an end to immorality, then there are 2 options:
- Put an end to the existence of people with immoral behaviour.
- Keep the immoral people alive but correct their behavior so that they stop behaving immorally afterwards.
Given these two options, an eternal punishment is nonsensical. Let's see why:
First, eternal punishment is not compatible with option 1. This conclusion is obvious: if someone is under eternal punishment, then that person must exist in the first place, so option 1 is incompatible with eternal punishment.
Second, eternal punishment is not compatible with option 2 either. Although it does keep people alive, it fails to correct people's behaviour: since the punishment never stops, people undergoing an eternal punishment are never given the chance to use the traumatic punishment feedback to correct their behaviour (they would have to wait an infinite amount of time before they change their behaviour, which is logically impossible). Therefore option 2 is not compatible with eternal punishment either.
Therefore, in a deterministic universe only temporary and accurately designed punishments would make sense. Accurately designed so that the person stops behaving immorally afterwards (otherwise it would be an unsuccessful and therefore unnecessary punishment).
A possible attempt of workaround would be to claim that determinism is false and that people behave non-deterministically. Then, you could say that people behave randomly. But if your decisions are random, then behaving morally or immorally would be a matter of chance: either you are lucky that your decision is moral by chance, or you are unlucky that your decision is immoral by chance. In such a random scenario, sending someone to an eternal punishment for behaving immorally would still not make sense. First of all, as argued for the deterministic case, options 1 and 2 are not compatible either. But with randomness the situation is even worse: even temporary punishment is nonsensical. In a deterministic universe at least you can use temporary punishments to correct people's behaviour, but in a non-deterministic/random universe, you cannot control future events with past events, since the premise of causality no longer holds. Therefore, if you punish someone today, that person might get unlucky and behave immorally by random chance tomorrow anyway.
Finally, if you claim that people have "free-will", then please give a formal definition of that term, explain how it is different from both randomness and determinism and finally show how it would justify an eternal punishment (if at all).